Question

我有一列的内存大小如Mb和kb。我想将所有值转换为R中的Mb。

$ Size : Factor w/ 462 levels "","1.0M","1.1M","0.98k"..

Answer 1

此答案假定您只有千字节和兆字节。这是一个可行的基础R解决方案：

input <- c("Varies with device", "9.4M", "201k", "0.98k")
output <- sapply(input, function(x) {
    ifelse(grepl("k$", x), paste0(0.001*as.numeric(sub("(\\d+(?:\\.\\d+)?)k", "\\1", x)), "M"), x)
})
output

[1] "Varies with device", "9.4M", "0.201M", "0.00098M"

此解决方案使用grepl查找所有匹配的千字节条目。对于此类条目，它将提取数字分量，转换为数字，然后按比例缩小一千以转换为兆字节。

Answer 2

有些笨拙，但这是可行的。如果GB或G稍后出现，则也应该起作用：

library(tidyverse)
library(stringr)

SampleData <- c("19M", "14M", "24M", "Varies with device", "1.1M", "9.4M", "Varies with device", "201k", "360k")

data <- tibble(strings = SampleData)

data %>%
 mutate(number = as.double(str_extract(strings, ".+(?=[:alpha:])")), #extract the numeric portion and make it a double variable
        letters = str_extract(strings, "[:alpha:]+"),
        number = if_else(letters == "k", number/1000, number),
        combined = paste0(number, "M"),
        strings = if_else(is.na(number), strings, combined)) %>%
 select(strings)


# A tibble: 9 x 1
  strings           
  <chr>             
1 19M               
2 14M               
3 24M               
4 Varies with device
5 1.1M              
6 9.4M              
7 Varies with device
8 0.201k            
9 0.36k

如何转换具有内存大小Ex的列。 MB和KB，我想要MB中的所有值吗？

2 个答案: